PORT CHARLOTTE, Fla. — Matt Harvey dazzled in his first spring start and fell back down to Earth in his next outing.

With his third spring training tune-up Monday against the Red Sox in Fort Myers, he knows the real thing is getting close.

“It’s nice knowing the pitch counts are increasing and the workload is going up,” Harvey said Sunday after the Mets lost to the Rays 8-4 at Charlotte Sports Park. “It’s a good sign we’re getting close to the season.”

The wait for Harvey has been longer than most after missing last season while recovering from Tommy John surgery.

“I’ve felt pretty normal from the first day,” said Harvey said. “Not pitching-wise, but being able to do all the normal stuff everyone else was doing — which I wasn’t able to do last year.”

“Certain weeks you feel a little bit better than others, especially during spring training,” Harvey said. “I talked to Dan about it and he said a lot of times your second start is a little sluggish. … Everything else feels great.”

Warthen said he wasn’t worried by Harvey’s relative ineffectiveness in his previous outing, saying he was “just up in the zone.”

And he has high expectations for Monday.

“I’m looking for him to go out there and be Matt Harvey again,” said Warthen, adding Harvey would begin to use his slider against the Red Sox.

“It’s going to be good to get over there and get used to their lineup a little bit,” Harvey said.

Bartolo Colon struggled with his fastball command and was roughed up for five runs in two innings Sunday in his third outing.

“I’m not worried about spring training results,” Colon said in a statement. “My arm feels good. That’s all I care about. … I was trying to get inside with my fastball and I didn’t do that as much as I wanted to.”

Collins called it “one of those days.”

“He lives and dies with command and sometimes it takes a little longer get it down,” said Collins, who noted Colon’s velocity was fine.

Lucas Duda returned to first base and went 0-for-4 with three strikeouts in his second game back from a rib injury… Travis d’Arnaud left Sunday’s game because of dizziness attributed to dehydration, although the catcher said he could have continued.